libsystemd-network: use domain validation instead of hostname validation for dhcp domain option

previously hostname_is_valid was used to validate domain names, which
would silently drop perfectly valid dns names that were longer than a
single dns label.

1 files changed, 11 insertions, 1 deletions

diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index 8a4220621b..d8bc76edda 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -32,6 +32,7 @@
 #include "dhcp-lease-internal.h"
 #include "sd-dhcp-lease.h"
 #include "network-internal.h"
+#include "dns-domain.h"
 
 int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) {
         assert_return(lease, -EINVAL);
@@ -504,9 +505,18 @@ int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
                 if (e)
                         *e = 0;
 
-                if (!hostname_is_valid(domainname) || is_localhost(domainname))
+                if (is_localhost(domainname))
                         break;
 
+                r = dns_name_is_valid(domainname);
+                if (r <= 0) {
+                        if (r < 0)
+                                log_error_errno(r, "Failed to validate domain name: %s: %m", domainname);
+                        if (r == 0)
+                                log_warning("Domain name is not valid, ignoring: %s", domainname);
+                        break;
+                }
+
                 free(lease->domainname);
                 lease->domainname = domainname;
                 domainname = NULL;